Month: August 2016

This is probably old news for some of you, but if you miss having Radio Shack around, Amazon is the new Radio Shack, including all the other electronics parts stores rolled into one.

If you are a regular Amazon buyer, you’ve probably noticed that the Chinese “quick and dirty” module and parts suppliers that started out on eBay have all opened stores on Amazon now as well. Being on Amazon generally means that they have to live up to a higher standard, if that kind of thing kept you from clicking the “Buy it Now!” button on eBay, but I’ve never gotten ripped off by any of them on eBay either.

Anyway, these guys offer just about anything imaginable for the Ham, DIY’er, or even an RF engineer like me. I’m truly amazed at all the parts and pre-made modules you can buy from them. If you have an Amazon Prime membership, which I highly recommend, you can buy just about anything and find it on your doorstep a day or two later, often without tax or shipping charges.

The prices are almost always way better than Radio Shack’s ever were. Here’s just one example: I needed to buy a 2.1 x 5.5 mm coaxial power plug–the type that you often see on the end of the “wall wart” power supplies. Looking on Amazon, I had tons of choices, including whether or not I wanted some with wires already soldered on them and ready to go. I finally chose these:

There are dozens of videos on YouTube showing how to build your own Bluetooth speakers or boom boxes. A number of them have ready-made Bluetooth radios and audio amps in common. These Bluetooth and audio amp modules are interesting because they are quite cheap (most under $20–see this one on Amazon as an example), fully built and tested, and easy to interface to. You could probably build one of these without even knowing how to solder! It’s a simple matter to fit one of these small BT/amp boards into a box with speakers you’d mount yourself, or even retrofitted into an old plastic-fantastic boom box you have laying around, or maybe purchase for next-to-nothing at a Goodwill store. All you really need is the housing and the pair of speakers. Everything else can go!

For those of you that are old enough, remember the little transmitters you could buy or build that output a fairly unstable signal somewhere on the 88 to 108 MHz FM broadcast band? They were often called FM or wireless mikes. Plug one in, and tune in to it on of your FM radios you happened to have around the house. They worked sort-of OK, but were never very good, and the 9V battery usually went dead in a few hours’ use. In the Bay Area, you also had lots of trouble finding a fairly open radio channel to use. The whole system was, as the British say, kind of fiddly. It was more of a science experiment than anything else..

With Bluetooth, it’s so much easier, and the sound is just light-years ahead of the old analog FM stuff! Most of us carry smart phones with Bluetooth built into them already, so it’s almost trivial to play the music or podcasts on your phone through your car stereo system or an inexpensive set of Bluetooth tabletop speakers. Most of the cheaper BT speakers don’t have such great sound, though. They tend to be small and tinny-sounding, but that’s not Bluetooth’s fault.

Anyway, here are several links to folks that have built their own Bluetooth speaker systems. Maybe they’ll inspire you to roll your own:

Here’s an under-$20 BT dongle that plugs in to any 3.5 mm jack, giving you instant Bluetooth audio for a home stereo system or maybe even a car stereo. This is sold by Parts Express (good company–lots of speakers and speaker kits as well), but there are many similar and cheaper units on Amazon as well:

Weekly Morgan Hill Amateur Radio Society Net, hosted by K7DAA and his band of merry followers from Morgan Hill, San Martin, Gilroy, Hollister, and beyond. The first Wednesday of every month is our Tech Night were we focus on a particular tech topic. The rest of the month (well, all the time, really) it is friendly chat, keeping up with ham news of the day, and seeing what's new with folks.

Weekly Morgan Hill Amateur Radio Society Net, hosted by K7DAA and his band of merry followers from Morgan Hill, San Martin, Gilroy, Hollister, and beyond. The first Wednesday of every month is our Tech Night were we focus on a particular tech topic. The rest of the month (well, all the time, really) it is friendly chat, keeping up with ham news of the day, and seeing what's new with folks.

Weekly Morgan Hill Amateur Radio Society Net, hosted by K7DAA and his band of merry followers from Morgan Hill, San Martin, Gilroy, Hollister, and beyond. The first Wednesday of every month is our Tech Night were we focus on a particular tech topic. The rest of the month (well, all the time, really) it is friendly chat, keeping up with ham news of the day, and seeing what's new with folks.

HF Night, AKA Ham Fun Night is a monthly gathering of like minded amateur radio peeps that like to meet and share ideas. Past meetings have included Lifepo4 battery information, how to do satellite contacts, antenna workshops, etc. Future topics will include a Skype meeting with Elecraft, and other interesting topics related to our hobby.

Weekly Morgan Hill Amateur Radio Society Net, hosted by K7DAA and his band of merry followers from Morgan Hill, San Martin, Gilroy, Hollister, and beyond. The first Wednesday of every month is our Tech Night were we focus on a particular tech topic. The rest of the month (well, all the time, really) it is friendly chat, keeping up with ham news of the day, and seeing what's new with folks.